Convert ESLint config to flat config format

[Copilot]

ESLint v9+ requires the new flat config format (eslint.config.js) instead of the legacy .eslintrc JSON format.

Changes

• New eslint.config.js: Migrated all rules to flat config format

  • Converted env/parserOptions to languageOptions with globals package
  • Replaced no-native-reassign → no-global-assign
  • Removed deprecated rules no longer in ESLint v9: no-catch-shadow, no-reserved-keys, no-new-object, newline-after-var, handle-callback-err, no-spaced-func, no-wrap-func, no-mixed-requires

• Deleted .eslintrc

// Before: .eslintrc (JSON)
{
  "env": { "node": true, "es2021": true },
  "parserOptions": { "sourceType": "module" },
  "rules": { ... }
}

// After: eslint.config.js (flat config)
const globals = require('globals');
module.exports = [{
  languageOptions: {
    sourceType: 'module',
    ecmaVersion: 2021,
    globals: { ...globals.node, arguments: 'writable' },
  },
  rules: { ... }
}];

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• api.zone.vision
  • Triggering command: /usr/local/bin/node node test.js (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

Original prompt

Convert the current old ESlint config to the new config format. Create a PR with the changes.

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✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.

[coveralls]

coverage: 100.0%. remained the same
when pulling 8456cba on copilot/convert-eslint-config-format
into c6f01f4 on develop.